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Social dominance hierarchy

The results likely represent the social dominance hierarchy within the cowherd. Five- and six-year-old cows are full grown and thus more dominant than younger cows. These cows can chase away other individuals that approach during calving.

Meanwhile, three-year-old cows are still rather inexperienced and calve in random places. Four-year-old cows retreat furthest from the herd, probably to avoid encounters with older, more dominant cows while calving.

These findings were rather surprising to the rancher. Cows were fed every morning and it was expected that younger cows would stay in close proximity to the herd and the feeding area.

The predicament that arises is that younger cows, which lack experience, subject themselves to increased predation pressure when they calve further away from the main herd. The bottom line is that in areas with predation, ranchers should keep their parturient cows in pastures in close proximity to the barn and monitor them frequently.

Cornelia Flörcke is a Colorado State University graduate research assistant.